A. Field of the Invention
The present invention relates generally to an automatic switching system for car cooler, or more precisely, to a mechanical switch in which a vacuum pressure of an engine is introduced to a disphragm room and the diaphragm which is enforced by a spring member is distorted by the vacuum pressure and a switching member which is attached to a center rod connected perpendicular to the center of the diaphragm is moved so that a contact of the car cooler is switched, thereby the car cooler is stopped in an acceleration period in which the maximum load is imposed on the engine and, in the period other than the acceleration, the car cooler is permitted to be workable.
B. Description of the Prior Art
A car cooler is mounted on a vehicle which runs about a hot region in summer so as to secure a comfortable driving. In such car cooler, a compressor of it is worked utilizing an engine output of the vehicle, so a faitly amount of load is imposed on the engine. Particularly in the period of acceleration of the vehicle, an extreme effort of the engine is needed for acceleration itself. So, it will be an excessive burden for the engine that the car cooler is being worked together with the acceleration, therefore, the degradation of the acceleration performance and increase of fuel consumption are resulted.
For resolving such problems, it will be wise to let the car cooler stop in acceleration period so as to decrease the load imposed on the engine. Then, such resolution will be good not only for the engine, but also for the cooling effect of the room of vehicle.
For the example of switching system of car cooler for such use, there are a turn switch which is manually operated and an automatic switching system which is turned on when the rotation number of the engine is more than 1,000 r.p.m. and turned off below that.
But, the manual switch for car cooler is not practical, because the operation for turning on and off is troublesome. By the automatic switching system which counts the rotation number of the engine, the car cooler can not be worked when the rotation number is about 600 r.p.m., for instance in the idling period of engine, accordingly, the cooling effect can not be expected when the car cooler is stopped. In other words, so long as the car cooler is turned on/off according to the rotation number of engine, the car cooler can not be worked or stopped in response to many kinds of driving conditions such as idling or so forth, although the car cooler is stopped in the acceleration period.